Device for drying prints, particularly copper prints



F. VON HEINRICH Filed Sept. 9, 1938 n hl s Hl h DEVICE FOR DRYING PRINTS, PARTICULARLY COPPER PRINTS Aug. 16, 1938.

Patented Aug. 16, 1938 more!) STATES PATENT @FE'EQE LARLY coerce. entries Friedrich von Heinrich, Budapest,

Application September 9, was, serial no. license in Austria September is, 12935 5 Claims.

The present invention relates to drying devices for prints and particularly to devices of this type in which the freshly printed sheets are conveyed from the press to a drying chamber comprising an endless conveyor with supporting grids for the sheets. Upon entering the drying chamber, the

sheets are transferred to the supporting grids,

which carry the sheets for a predetermined time through a dry hot atmosphere whereupon the dried sheets are discharged irorn the dryinz, chamber.

One object of the present invention is to produce a drying apparatus of this type in which the drying process is highly intensified.

The secondobiect is to produce a device in which the sheets are securely retained on the supporting grids. 7

Still another object of the present invention is produce a drying device in which the distance of the individual supporting grids from one another is substantially reduced whereby the same output can be obtained willie. drying chamber or substantially smaller dimensions.

Uther objects will become apparent from the I following detailed description of one embodiment of the invention illustratively exemplified in the accompanying drawing, in which 1' shows the device in a vertical section, on a greatly reduced scale with only one group of conveying grids being represented;

Fig. 2 is a side view or one part of the conveyor device, on a less reduced scale; and

Fig. 3 shows a front view of two linlr. elements with flat bars, grid rods and sheet retaining arms,

' on the original scale.

The freshly printed sheets, which leave for instance a copper plate press (not shown), rail onto a conveyor 9 (Fig. l) This conveyor carries the individual sheets directly into the drying apparatus built into a heat insulated casing The casing 2 contains the following constructional parts: two lateral supports, which in the elevation according to Fig. 1 are placed rearwardly of one another and for the sake of clearness are not shown; two horizontal shafts. i], ii arranged one above the other and rotatably mounted in the supports; a conveyor b for the sheets to be dried, passing around said shafts; tour fans 5 for maintaining the circulation of the hot drying air; and two sets of heating units 3. The finished dried prints are discharged from the drying chamber by means of a further conveyor 8, Q and deposited in a box It.

The conveyor 5 comprises four endless pairs of conveyor chains IE, IT, l8, l9 (Fig. 2), which are horizontally arranged one inside the other and pass around the shafts 3, 3 (Fig. i). The chains themselves consist of special link elements it (Fig. 3), into which fiat iron bars ii are firmly, inserted, so that the oppositely disposed linlrs iii of each pair of chains carry a. single bar. From the outer edge of each bar, there project outwardly firmly gripped rods it, which form a kind of grid on each fiat bar ii. At the lower and upper turning points of the chain the grids passing around these points separate radially from the adjacent grids.

The fresh prints pass individually from the conveyor linto the spaces between two adjacent grids at the lower turning point of the chain. Each grid picks up one paper sheet and carries it upwardly on the right strand of the chain. The fans draw the air from the space it! be tween the two strands of the chains, whereby the air withdrawn is replaced by fresh air passing through the interstices between the fiat bars ii. The fans 5 convey the air to the heater batteries ii. The air, after passing over the heater batteries, returns over the sheets on the grids through the interstices of the flat bars and then repeats the above described continuous circulation.

When the sheets reach the upper turning point of the chain, they will already be suficiently dry to turn over at this highest point without danger of becoming damaged and each sheet falls onto the preceding grid with its printed side downwards. In order to prevent the sheets at the upper turning point from falling between the bars ii, appropriately bent wire arms it (Fig. 3) are provided on the fiat bars ii of the grids at a plurality oi places, which arms M being bent perpendicularly to the planes of the grids, overlap the space between the grids.

In the descending left strand of the conveyor i (Fig. 1) a further drying of the prints and especially of the color takes place. The finished dried prints, on the side of the lower turning point opposite to the feed side, fall on to the conveyor E3, 9 and are stacked as already mentioned.

As may be seen in Fig. 3, the distance a between any two consecutive grids it carried by a single pair of chains, cannot, for reasons of stability, etc., be reduced to less than several centimetres. In the embodiment of the invention shown in the drawing, however, this distance is divided into four equal parts, for which purpose the pairs of chains Hi to i9 (Fig. 2) are staggered relative to one another in the direction of their movement to the extent of one quarter of the 1. A device for drying printed paper sheets,-

comprising a housing provided with openings in the lower portions of two opposite walls for the introduction of the wet sheets and the removal of the dry sheets, a vertical conveyor in said housing including an endless conveyor chain having radially projecting grids adapted to receive and to carry the paper sheets, means to conduct hot air from both sides in substantially horizontal paths to the outer edges of said grids, and suction means between the two sides of said conveyor chain, to give a relatively high speed to the hot air striking the paper sheets on said grids.

2. A device for drying printed paper sheets, comprising a housing provided with openings in the lower portions of two opposite walls for the introduction of the wet sheets and the removal of thedry sheets, a vertical conveyor in said housing, said conveyor including a pair of parallel conveyor chains spaced from each other, horizontal bars connecting the corresponding links of both chains, each of said bars having a plurality of parallel radially projecting rods forming grids to receive and to carry the paper sheets,

means to conduct hot air from both sides in substantially horizontal paths to the outer edges 01 said grids and suction means between the two sides of said conveyor chain to give a relatively high speed to the hot air striking the paper sheets on said grids.

3. A device, as claimed in claim 2, in which said means to conduct hot air'to the outer edges of said grids includes radiators arranged in said housing on both sides of the conveyor adjacent the free edges of the grids and conductors leading the air to be heated to said radiators.

4. A device, as claimed in claim 2, comprising further arms projecting radially from said horizontal bars intermediary said grid rods, said arms being bent at a right angle to overlap the distances between consecutive grids and to prevent the paper sheets from being sucked inwardly beyond said horizontal bars.

5. A device for drying printed paper sheets, comprising a conveyor including a pair of parallel conveyor chains spaced from each other, horizontal bars, connecting the corresponding links of both chains and carrying radially projecting grids, said bars filling a fraction of the longitudinal space occupied by the corresponding links, at least one additional pair of chains arranged parallel to said first pair of chain and angularly staggered with respect to the latter by a fraction of one link, said additional chains having grid carrying horizontal bars, in the spaces between the horizontal bars of said first mentioned pair of chains.

FRIEDRICH VON HEINRICH. 

